n = int(input())
if n >= 30 :
    print("Yes")
else:
    print('No') n = int(input()) n int(input()) int input() input if n >= 30 :
    print("Yes")
else:
    print('No') n >= 30 n 30 print("Yes") print "Yes" print('No') print 'No' n = int(input()) int(input()) n
n = int(input())
if n >= 30 :
    print("Yes")
else:
    print('No')